Alkyl ethanolamine and biocide combination for hydrocarbon based fuels

ABSTRACT

A microorganism control combination for liquid hydrocarbon systems containing water is disclosed. The combination is a biocidal control agent and an alkylamine ethoxylate of the formula 
 
R X N(CH 2 CH 2 OH) Y  
 
wherein R is C 3  to C 18  alkyl or isoalkyl group, X and Y are 1 or 2, Z is 0 or 1, X+Y is not greater than 3, when X or Y is 2 than Z is 0 and when X is 2 the R groups are the same or different C 3  to C 18  alkyl or isoalkyl groups. The combination provides effective microorganism control with reduced concentration of biocidal control agent.

This application is a continuation in part of U.S. application Ser. No.10/886,866 filed Jul. 8, 2004.

FIELD OF THE INVENTION

The present invention relates to additives for systems of hydrocarbonfuels containing water. More particularly, the present invention relatesto biocidal treatments for water-hydrocarbon based fuel emulsions andhydrocarbon based fuels, such as diesel or biodiesel systems containingwater. The treatment comprises at least one biocidal alkyl ethanolamineagent or a combination of a biocidal agent and at least one alkylethanolamine.

BACKGROUND OF THE INVENTION

The performance of hydrocarbon based fuels such as diesel fuels,gasoline and kerosene can be favorably modified by the addition ofperformance enhancing additives such as water (emulsified fuel),emulsifiers, biocides, pH modifiers, detergents, etc. Two areas ofcurrent commercial interest are the formulation of emulsified dieselfuel and the use of plant derived diesel fuel alternatives known asbiodiesel. In diesel engines, the high temperatures reached duringcombustion may increase the tendency for the production of nitrogenoxides (NO_(x)) and sulfur oxides (SO_(x)).

Nitrogen oxides are formed via the reaction of atmospheric nitrogen andoxygen in the combustion chamber and, to a far lesser extent, fromoxidation of organic nitrogen species in the fuel. The rates at whichvarious NO_(x) type species form are related to combustion temperature,and it has been found that a small reduction in flame temperature canresult in a large reduction in the production of nitrogen oxides.

One approach to lowering flame temperature is to inject water into thecombustion chamber. This method allows for existing fuels to be used asis, but it requires costly and complicated changes in engine design. Asan alternative, one may use fuels that comprise an emulsion of bothwater and traditional petrodiesel (derived from a petroleum refiningprocess) and/or biodiesel fuel (derived from transesterification ofplant or animal derived triglycerides). One problem that exists in suchwater-hydrocarbon based fuel emulsions is the growth of microorganismsthat utilize the mostly hydrocarbon based fuel as a nutrient. Suchmicroorganisms or microbes will tend to grow in the water phase, butthey can also become dispersed in the hydrocarbon fuel phase leading todegradation of the hydrocarbon fuel. In the case of biodiesel,microorganisms can grow in the pure fuel with just the traces of waternaturally present as a contaminant (typical water specification forbiodiesel is 50 ppm). All such contamination or degradation can causesludge formation that clogs fuel filters and other engine components.

In addition to the growth of microorganisms or microbes inwater-hydrocarbon based fuel emulsions and/or biodiesel type fuels,similar problems arise in other water-hydrocarbon based fuel interfacesituations. For example, hydrocarbon based fuels are frequently exposedto a layer of water in large storage and/or transportation vessels. Theinterface between the water and hydrocarbon product becomes a breedingground for microorganisms and microbes.

U.S. Pat. No. 3,883,345 disclosed the use of a bactericidal agent suchas an alkyl pyridinium or picolinium halide to inhibit microorganismrelated sludge in fuel oils.

UK patent number 1,325,913 discloses the use of a condensation productof an aliphatic aldehyde such as formaldehyde and a primary or secondaryalkanolamine such as diethanolamine to control microorganisms inhydrocarbon fuels.

U.S. Pat. No. 6,607,566 discloses a method for producing a highly stableaqueous fuel emulsion. The fuel emulsion can include corrosioninhibitors including alkanolamines for pH control as well as biocides.

SUMMARY OF THE INVENTION

US Patent Application Publication number U.S. 2003/0162845 A1 disclosesthe use of de-activatable biocides in hydrocarbonaceous products.

The present invention relates to a treatment for water-hydrocarbon basedfuel system, which provides in part, biocidal control. Moreparticularly, the present invention relates to the addition of acombination of a biocide and at least one alkyl ethanolamine to awater-hydrocarbon based fuel system to inhibit microbiological activity.In hydrocarbon based fuel systems, contact with water eitherintentionally or through contamination can result in undesirablebiological activity. The microbiological activity can result indegradation of the fuel, sludge formation, undesirable odor generation,etc. The use of biocidal agents in such systems is known. The presentinventors have discovered that the addition of a combination of abiocidal agent and at least one alkyl ethanolamine to such systemsresults in unexpected increased biocidal activity. The combination ofthe present invention can allow a reduction in the amount of biocidenecessary to achieve a given level of control. The alkyl ethanolamine,in addition to enhancing the activity of the biocide, also can providepH control for the system. Such pH control can reduce possible corrosionproblems. The favorable impact of the amine is particularly important inthe plant-derived fuels known generically as biodiesel.

The biocidal agent-alkyl ethanolamine treatment of the present inventioncan be employed in combination with conventional additives forhydrocarbon fuel systems containing water such as water-hydrocarbonemulsion systems and/or non-emulsion fuels containing or contaminatedwith small amounts of water. Conventional additives can includeemulsifiers, detergents, pH adjusting agents, etc. The treatment of thepresent invention can be employed in systems containing hydrocarbonbased fuels such as diesel fuel, gasoline, kerosene, heating oils, etc.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Formulated hydrocarbon fuels in general and emulsified hydrocarbon fuelsin particular are prone to degradation via microbiological contaminationor attack. In hydrocarbon fuel systems where water is present,microorganism growth can occur at the water-hydrocarbon interface. Themicroorganism can degrade the quality of the hydrocarbon, causeundesirable odors and cause sludge formation. The treatment of suchsystems with biocidal control agents is known. The present inventorsdiscovered that the efficacy of biocidal agents in such systems could beenhanced through the addition of alkyl ethanolamines. As used herein,biocide or biocidal agent refers to any substance that kills or inhibitsthe growth of microorganisms such as bacteria, molds, slimes, fungi andthe like.

In hydrocarbon fuel systems where water is present as a contaminant, thewater or aqueous phase can comprise between 0.01% and 25% by weight ofthe system. Such water contamination can result from condensation inlarge storage or transportation vessels. In addition, such contaminationcan result from non-exclusive use of storage tanks. In addition towater-hydrocarbon fuel systems resulting from contamination, suchsystems may be formed intentionally. For example, the formation ofwater-diesel fuel emulsions to control NO_(x) and SO_(x) emissions isknown. The use of additives including biocides in such systems is known.

The present inventors have discovered that the combination of an alkylethanolamine and a biocide in such systems significantly enhances theefficacy of the biocide. The use of the combination of the presentinvention allows for a decrease in the amount of biocide needed toprovide a desired level of control, or an increase in the level ofbiocidal control without an increase in the amount of biocide employed.

The alkyl ethanolamines of the present invention are of the formula:R_(X)NH_(Z)(CH₂CH₂OH)_(Y)wherein R is C₃ to C₁₈ alkyl or isoalkyl group, X and Y are 1 or 2, Z is0 or 1, X+Y is not greater than 3, when X or Y is 2 than Z is 0 and whenX is 2 the R groups are the same or different C₃ to C₁₈ alkyl orisoalkyl groups. Preferred alkyl ethanolamines include butyldiethanolamine, Butylaminoethanol, dibutylaminoethanol anddiisopropylaminoethanol. The alkylamine ethoxylate can be added towater-hydrocarbon based fuel systems at treatment concentrations fromabout 100 to 8000 parts per million (ppm) and preferably at treatmentconcentrations of from about 1000 to 5000 ppm.

The alkyl ethanolamine is added to a water-hydrocarbon based fuel systemin combination with a biocide. The biological control agent can includetriazines, thiazolinones, halogenated compounds, thiocyanates,carbamates, pyrithiones, quaternary ammonium compounds, aldehydes,heterocyclic compounds, soluble metal ions and reactive alkylatingagents. A preferred biocide is a 78.5% 1,3,5-(2-hydroxyethyl)-s-triazinesolution in water available as GROTAN® from Troy Chemicals. Othersuitable biocides may comprise benzoisothiazolone such as Proxel DB20, a20% suspension of benzoisothiazolone available from Avecia, and thelike. The biocide can be added in concentrations from about 100 to over2000 ppm. However, to minimize potential adverse environmental impact,it is preferred to use lower levels of biocide. In the combination ofthe present invention, biocide concentrations of from about 100 ppm toabout 1500 ppm have been found to be effective. In cases wherein thebiological challenge is minimal, the alkyl ethanolamines of the presentinvention may be used as the sole biological control agent.

The biocide-alkyl ethanolamine combination of the present invention, inaddition to providing enhanced biocidal control also will provide pHcontrol in water-hydrocarbon based fuel systems. The alkyl ethanolaminecomponent of the present invention can provide pH control that inhibitscorrosion in hydrocarbon based fuel systems containing water. Thetreatment combination of the present invention can be employed inconcert with other system additives such as emulsifiers, detergents, pHadjusting agents, etc.

The present invention will be further described by the followingnon-limiting examples.

EXAMPLES Example 1

A 324 well microtiter plate was employed to evaluate the growth of amicroorganism common to water-hydrocarbon based fuel systems,Pseudomonas Aeruginosa (ATCC27853) in with a variety of amines atvarying concentrations. The testing employed Trypticase Soy Broth (TSB)as a growth medium and 25 m molar tris (trihydroxymethylmethylamine) asa buffer. The test duration was 24 hours at pH 8.5.

The amines tested were alkyl ethanolamines: butyldiethanolamine (BDEA),butylaminoethanol (BAE), tert-butylaminoethanol (TBAE) anddiisopropylaminoethanol (DIPAE). Alkyl alkanolamines,2-methyl-2-amino-1-propanol (AMP),) and diglycolamine (DGA) were alsotested. The biocide was GROTAN® available from Troy Chemicals of NewJersey. Table I summarizes the test results. The entries in Table 1 areaverages of at least four replicate runs for each test. TABLE 1 GROTANGROTAN GROTAN GROTAN GROTAN GROTAN 0 ppm 100 ppm 250 ppm 500 ppm 1000ppm 2000 ppm Bacteria/ 0.97 1.19 1.21 0.88 0.36 0.39 media Plus 20004000 2000 4000 2000 4000 2000 4000 2000 4000 2000 4000 Amine ppm ppm ppmppm ppm ppm ppm ppm ppm ppm Ppm ppm BDEA 0.67 0.45 0.52 0.67 0.72 0.510.79 0.30 0.32 0.28 0.33 0.33 DIPAE 0.59 0.46 0.56 0.42 0.52 0.41 0.520.28 0.31 0.28 0.35 0.36 BAE 0.37 0.49 0.49 0.35 0.45 0.32 0.35 0.250.30 0.29 0.36 0.36 AMP 0.72 1.12 0.72 0.72 0.72 0.69 0.72 0.39 0.310.30 0.35 0.37 TBAE 0.67 0.55 0.72 0.58 0.69 0.59 0.83 0.34 0.30 0.280.35 0.36 DGA 0.76 0.68 0.71 0.70 0.70 0.69 0.76 0.36 0.32 0.29 0.340.36

The data in Table I shows that the alkyl ethanolamines BAE, BDEA andDIPAE provide an enhancement in the biocidal effect of GROTAN® that isnot seen in alkyl alkanolamines AMP and DGA.

Example 2

A culture of mixed enteric bacteria (klebsiella pneumoniae, Proteusvulgarus, Citrobacter sp., Escherichia coli) at pH=9.0 in TSB(trypticase soy broth) media mixed with emulsified oil was prepared. Abiocide, GROTAN® {78.5% 1,3,5-(2-hydroxyethyl)-s-triazine solution inwater} as sold by Troy Chemicals (Florham Park, N.J.) was added atvarying concentrations to the culture in combination with 2500 ppm ofone of the four alkanolamines, N-butylaminoethanol (BAE), diethanolamine(DEA), diglycolamine (DGA) or 2-amino-2-methyl-1-propanol (AMP). Opticaldensity measurements were taken every 15 minutes over a 24 hour timeperiod (total of 96 data points). The maximum growth slope wascalculated by taking the 10 contiguous data points that result in thehighest growth slope (units of OD per time) over the 24 hour period.Those 10 data points were subjected to a least squares linear fit tocalculate the maximum growth slope. Table 2 summarizes the maximumgrowth slopes for these tests. TABLE 2 [Biocide] BAE DEA DGA AMP 1650ppm 0.0515 0.117 0.0725 0.069 650 ppm 0.082 0.466 0.1955 0.32 0 ppm 0.20.723 0.796 1.065

The data in Table 2 shows that the bacteria growth rate can be slowedsignificantly with reduced levels of biocide when an alkyl ethanolamineis combined with the biocide.

Example 3

A culture of Pseudomonas aeruginosa (ATCC 10145) at pH=8.5 in TSB(trypticase soy broth) media was prepared. The biocide Proxel DB20 (20%suspension of benzoisothiazolone (BIT) in water), as sold by Avecia, wasadded at varying concentrations in combination with 1000 ppm or 2000 ppmof the alkanolamines N-butylaminoethanol (BAE),2-amino-2-methyl-1-propanol (AMP), dibutylaminoethanol (DBAE) orn-octylaminoethanol (OAE). Optical density measurements were taken every15 minutes over a 24 hour time period (total of 96 data points). Themaximum growth slope was calculated by taking the 10 contiguous datapoints that result in the highest growth slope (units of OD per time)over a 24 hour period. Those 10 data points were subjected to a leastsquares linear fit to calculate the maximum growth slope. Table 3summarizes the maximum growth slopes for these tests. TABLE 3 AMP BAEDBAE OAE 1000 2000 1000 2000 1000 2000 1000 2000 BIT ppm ppm ppm ppm ppmppm ppm ppm 0 ppm 0.478 0.29 0.333 0.000 0.228 0.114 0.000 0.000 150 ppm0.667 0.361 0.317 0.134 0.221 0.084 0.000 0.000 250 ppm 0.508 0.3200.353 0.000 0.255 0.104 0.000 0.000 500 ppm 0.407 0.228 0.281 0.0000.143 0.000 0.000 0.000

The data in Table 3 shows that the bacteria growth rate can be slowedsignificantly with reduced levels of biocide when an alkyl ethanolamineis combined with the biocide.

Example 4

A culture of Pseudomonas aeruginosa (ATCC 10145), a bacteria common inwater-oil systems, at pH 8.5 in Tris buffer was prepared in TSB media.Biological control agent Bronopol (2-nitro-2-bromo-1,3-propanediol) atvarying concentrations in combination with alkanols BAE and AMP at 2000ppm was added and bacteria growth monitored via optical density as inExample 3. Table 4 summarizes the maximum growth slope: TABLE 4[Bronopol] 35 ppm 25 ppm 15 ppm 5 ppm AMP (2000 ppm) 0 0 0.327 0.345 BAE(2000 ppm) 0 0 0 0.083

The data in Table 4 shows that the bacteria growth rate can be slowedsignificantly with reduced levels of biocide when an alkyl ethanolamineis combined with the biocide.

Example 5

The impact of various N-alkyl alkanolamines on the control of thebacterial species Mycobacterium smegmatis (ATCC # 19420), a bacteriacommon in water-oil systems, was evaluated by measuring opticalabsorbance of samples treated with various concentrations of N-alkylalkanolamines. Bacterial concentration in the experimental media,consisting of a standardized solution of clear nutrient broth(Middlebrook 7H9), amine, buffer (Tris) and water, was monitoredindirectly via optical absorbance at 590 nm. The pH was adjustedinitially to 8.5 with Tris buffer. An additional absorbance reading at750 nm was used to insure that light scattering and turbidity were notadversely affecting the data. A tetrazolium dye was employed to increasethe sensitivity of the optical measurement. The values reported in Table1 are end-point optical densities in milliOD units after 72 hours. InTable 1, AMP is 2-amino-2-methyl-1-propanol, BAE is butylaminoethanol,DBAE is dibutylaminoethanol, OAE is octylaminoethanol. The first columnin Table 1 gives the treatment amine concentration in parts per millionby weight. TABLE 5 [Amine] (ppm) AMP BAE DBAE OAE 470 2100 2200 2000 0940 2200 2100 2000 0 1880 2100 2000 2000 0 3750 2000 1900 1900 0 75001700 1700 1200 0

It is clear from the data shown that OAE is markedly more effective thanAMP against Mycobacteria.

Example 6

The impact of N-alkylalkanolamines on the control of the bacterialspecies Mycobacterium smegmatis (ATCC # 19420), a bacteria common inwater-oil systems, was evaluated by measuring optical absorbance ofsamples treated with various alkyl ethanolaminesisDCHA=Dicyclohexylamine, OAE=Octylaminoethanol, ODEA=Octyldiethanolamine.Bacterial concentration was monitored indirectly via optical absorbanceat 660 nm. The values reported are end-point optical densities inmilliOD units after 48 hours. The media consisted of a standardizedsolution of clear nutrient broth (Middlebrook 7H10 with OADCsupplement), amine, buffer (Tris) and water. The pH was adjustedinitially to 8.5 with Tris buffer. The first column in the Table givesthe amine concentration in ppm. The final two columns give data forcells that also contained 2 grams per liter of boric acid. In all cases,the values are averages of at least three replicates. The final row ofthe Table gives an estimate of the concentration range in which theamine in question starts to inhibit the growth of this bacterialspecies. TABLE 6 OAE DCHA [Amine] Boric Boric (ppm) OAE ODEA DCHA AcidAcid 0 1.13 1.13 1.13 0.925 0.925 500 0.184 0.847 1.02 0.100 1.125 10000.149 0.117 0.802 0.121 0.855 1500 0.213 0.260 0.995 — — 2000 0.2260.225 0.268 0.015 0.085 4000 0.205 — — — — MIC <500 500-1000 1500-2000<500 1000-2000 (ppm)

Example 7

The impact of the N-alkylalkanolamines of Example 6 on the control ofthe bacterial species Mycobacterium marinum (ATCC # 19420), bacteriacommon in water-oil systems, was evaluated as described above in Example6. Bacterial concentration in the experimental media was monitoredindirectly via optical absorbance at 660 nm. The values reported areend-point optical densities in milliOD units after 72 hours. The mediaconsisted of a standardized solution of clear nutrient broth(Middlebrook 7H10 with OADC supplement), amine, buffer (Tris) and water.The pH was adjusted initially to 8.5 with Tris buffer. The first columnin the Table gives the amine concentration in ppm. In all cases, thevalues are averages of at least three replicates. The final row of theTable gives an estimate of the concentration range in which the amine inquestion starts to inhibit the growth of this bacterial species. TABLE 7[Amine] (ppm) OAE ODEA DCHA BAE 0 0.8 0.8 0.8 0.8 400 0.4 0.6 0.6 — 8000.4 0.4 0.6 0.7 1200 0.4 0.4 0.5 0.7 2000 0 0.1 0.4 0.6 4000 0 0 0.4 0.6MIC (ppm) 1200-2000 1200-2000 >4000 >4000

Example 8

The impact of N-alkylalkanolamines on the control of the bacterialspecies Aureobasidium pullulans (ATCC 12536), a bacteria common inwater-oil systems, was evaluated by measuring optical absorbance ofsamples treated with various concentrations of N-alkyl alkanolamines.Biological control agent −50 ppm MIT/CMIT(2-methyl-4-isothiazolin-3-one/2-methyl-5-chloro-4-isothizolin-3-one)was employed in combination with the alkanols as listed previously atconcentrations designated in Table 8. SAB media at pH 8.5 (Tris buffer)was employed. Table 8 summarizes measurement of end-point opticaldensity after 24 hours and 48 hours: TABLE 8 End Point 24 hours 48 hoursAMP (1000 ppm) 0.3 0.4 AMP (2000 ppm) 0.3 0.4 BAE (1000 ppm) 0.3 0.3 BAE(2000 ppm) 0.2 0.2 DBAE (1000 ppm) 0.3 0.4 DBAE (2000 ppm) 0.2 0.2 OAE(200 ppm) 0.1 0.1 OAE (500 ppm) 0 0

While the present invention has been described with respect toparticular embodiments thereof, it is apparent that numerous other formsand modifications of this invention will be obvious to those skilled inthe art. The appended claims and this invention generally should beconstrued to cover all such obvious forms and modifications, which arewithin the true spirit and scope of the present invention.

1. A method of inhibiting the growth of microorganisms in a liquidhydrocarbon system containing water comprising adding to said system abiocidially effective amount of a combination of a biocidal agent and atleast one alkyl ethanolamine of the formulaR_(X)NH_(Z)(CH₂CH₂OH)_(Y) wherein R is C₃ to C₁₈ alkyl or isoalkylgroup, X and Y are 1 or 2, Z is 0 or 1, X+Y is not greater than 3, whenX or Y is 2 than Z is 0 and when X is 2 the R groups are the same ordifferent C₃ to C₁₈ alkyl or isoalkyl groups.
 2. The method of claim 1wherein said liquid hydrocarbon system contains 0.01% to 25% water. 3.The method of claim 1 wherein said liquid hydrocarbon is diesel fuel,biodiesel fuel, mixed diesel/biodiesel fuel, heating oil, jet fuel orkerosene.
 4. The method of claim 1 wherein said biocidal agent isbenzisothiazolin-3-one.
 5. The method of claim 1 wherein said biocidalagent is 2-methyl-5-chloro-4-isothiazolin-3-one.
 6. The method of claim1 wherein said biocidal agent is 2-(thiocyanomethylthio)-benzothiazole.7. The method of claim 1 wherein said alkylamine ethoxylate is butyldiethanol amine, butylaminoethanol, diisopropylaminoethanol,dibutylaminoethanol or mixtures thereof.
 8. The method of claim 1wherein the ratio of biocidal agent to alkylamine ethoxylate is fromabout 1:50 to about 2:1.
 9. The method of claim 1 wherein said biocidalagent is added in a concentration of about 100 ppm to about 8000 ppm ofsaid system.
 10. The method of claim 1 wherein said biocidal agent isadded in a concentration of about 1000 ppm to about 5000 ppm of saidsystem.
 11. The method of claim 1 wherein said liquid hydrocarbon systemfurther comprises emulsifiers, detergents, pH adjusting agents ormixtures thereof.
 12. A microorganism control combination comprising abiocidal agent and at least one alkyl ethanolamine of the formulaR_(X)N(CH₂CH₂OH)_(Y) wherein R is C₃ to C₁₈ alkyl or isoalkyl group, Xand Y are 1 or 2, Z is 0 or 1, X+Y is not greater than 3, when X or Y is2 than Z is 0 and when X is 2 the R groups are the same or different C₃to C₁₈ alkyl or isoalkyl groups.
 13. The method of claim 12 wherein saidalkylamine ethoxylate is butyl diethanol amine, butylaminoethanol,diisopropylaminoethanol, dibutylaminoethanol or mixtures thereof. 14.The method of claim 12 wherein the ratio of biocidal agent to alkylamineethoxylate is from about 1:50 to about 2:1.
 15. The method of claim 12wherein said microorganism control combination further comprisesemulsifiers, detergents, pH adjusting agents or mixtures thereof.
 16. Amethod of inhibiting the growth of microorganisms in a liquidhydrocarbon system containing water comprising adding to said system abiocidially effective amount of at least one alkyl ethanolamine of theformulaR_(X)NH_(Z)(CH₂CH₂OH)_(Y) wherein R is C₃ to C₁₈ alkyl or isoalkylgroup, X and Y are 1 or 2, Z is 0 or 1, X+Y is not greater than 3, whenX or Y is 2 than Z is 0 and when X is 2 the R groups are the same ordifferent C₃ to C₁₈ alkyl or isoalkyl groups.
 17. The method of claim 16wherein liquid hydrocarbon system contains 0.01% to 25% water.
 18. Themethod of claim 16 wherein said liquid hydrocarbon is diesel fuel,biodiesel fuel, mixed diesel/biodiesel fuel, heating oil, jet fuel orkerosene.
 19. The method of claim 16 wherein said alkylamine ethoxylateis butyl diethanol amine, butylaminoethanol, diisopropylaminoethanol,dibutylaminoethanol or mixtures thereof.
 20. The method of claim 16wherein said at least one alkyl ethanolamine agent is added in aconcentration of about 100 ppm to about 8000 ppm of said system.
 21. Themethod of claim 16 wherein said at least one alkyl ethanolamine agent isadded in a concentration of about 1000 ppm to about 5000 ppm of saidsystem.
 22. The method of claim 16 wherein said system further comprisesemulsifiers, detergents, pH adjusting agents or mixtures thereof.